diff --git a/pubspec.yaml b/pubspec.yaml
index 3d48447..9ec80f4 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,9 +1,9 @@
 name: collection
-version: 0.9.4
+version: 1.0.0
 author: Dart Team <misc@dartlang.org>
 description: Collections and utilities functions and classes related to collections.
 homepage: http://www.dartlang.org
 environment:
-  sdk: '>=1.0.0 <2.0.0'
+  sdk: '>=1.5.0 <2.0.0'
 dev_dependencies:
   unittest: '>=0.9.0 <0.11.0'